In general, a touch device comprises a light emitting module and a touch panel, wherein the light emitting module is composed of a plurality of light emitting elements and at least a light guide plate, and the touch panel can be divided into capacitive touch panels, resistive touch panels and optical touch panels. Compared with the capacitive touch panels and the resistive touch panels, the cost of the optical touch panels are lower and thus have an advantage of higher economic benefit.
FIG. 1 illustrates a structural top view of a conventional optical touch panel. Referring to FIG. 1, the conventional optical touch panel 10 comprises a contact plate 101, a plurality of first light emitting elements 102, a plurality of second light emitting elements 103, a plurality of first optical sensing elements 104, a plurality of second optical sensing elements 105, a first circuit board 106, a second circuit board 107, a third circuit board 108 and a fourth circuit board 109, a first control unit 110 and a second control unit 111. The contact plate 101 is capable of being contacted by at least a finger of a user or by a stylus. The plurality of first light emitting elements 102 are capable of generating a plurality of first light beams B1, wherein the plurality of first light beams B1 travel along a horizontal direction and are transmitted over the contact plate 101. The plurality of second light emitting elements 103 are capable of generating a plurality of second light beams B2, wherein the plurality of second light beams B2 travel along a vertical direction and are transmitted over the contact plate 101. Herein, each of the plurality of first light emitting elements 102 and the plurality of second light emitting elements 103 is an infrared light emitting source, and each of the first light beams B1 and the second light beams B2 is an infrared light and invisible by the user.
As illustrated in FIG. 1, the first circuit board 106 is disposed at a left side of the contact plate 101 and capable of disposing the plurality of first light emitting elements 102 thereon. In addition, the third circuit board 108 is disposed at a right side of the contact plate 101 and capable of disposing the plurality of first optical sensing elements 104 and the first control unit 110 thereon. Herein, each of the first light emitting elements 102 corresponds to one of the first optical sensing elements 104, and the first control unit 110 connects with each of the plurality of first optical sensing elements 104. Besides, the second circuit board 107 is disposed at an upper side of the contact plate 101 and capable of disposing the plurality of second light emitting elements 103 thereon. Moreover, the fourth circuit board 109 is disposed at a lower side of the contact plate 101 and capable of disposing the plurality of second optical sensing elements 105 and the second control unit 111 thereon. Herein, each of the second light emitting elements 103 corresponds to one of the second optical sensing elements 105, and the second control unit 111 connects with each of the plurality of second optical sensing elements 105.
The plurality of first optical sensing elements 104 are capable of receiving the plurality of first light beams B1 from the plurality of first light emitting elements 102 and then converting the received first light beams B1 from a form of light energy into electrical signals in a form of electrical energy, so as to output the corresponding electrical signals to the first control unit 110. Similarly, the plurality of second optical sensing elements 105 are capable of receiving the plurality of second light beams B2 from the plurality of second light emitting elements 103 and then converting the received second light beams B2 from a form of light energy into electrical signals in a form of electrical energy, so as to output the corresponding electrical signals to the second control unit 111.
When the conventional optical touch panel 10 is activated and the contact plate 101 is untouched, the plurality of first light emitting elements 102 generate a plurality of first light beams B1, and the plurality of first light beams B1 are transmitted over the contact plate 101 and thus respectively received by the corresponding one of the plurality of first optical sensing elements 104, so that the plurality of first optical sensing elements 104 output the electrical signals corresponding to the first light beams B1 to the first control unit 110. On the other hand, the plurality of second light emitting elements 103 generate a plurality of second light beams B2, and the plurality of second light beams B2 are transmitted over the contact plate 101 and thus respectively received by the corresponding one of the plurality of second optical sensing elements 105, so that the plurality of second optical sensing elements 105 output the electrical signals corresponding to the second light beams B2 to the second control unit 111.
FIG. 2 illustrates a structural top view of a conventional optical touch panel being touched.
Referring to FIG. 2, when the conventional optical touch panel 10 is activated and a specific point of the contact plate 101 is touched by the finger F of the user, the first light beam B1 generated by the third one of the plurality of first light emitting elements 102 is interrupted by the finger F of the user. Therefore, the interrupted first light beam B1 is unable to be received by the corresponding one of the plurality of first optical sensing elements 104, and the remaining first light beams B1 other than the interrupted first light beam B1 generated by the third one of the plurality of first light emitting elements 102 are respectively received by the corresponding one of the plurality of first optical sensing elements 104, and thus only those of the first optical sensing elements 104 receiving the first light beams B1 output the corresponding electrical signals to the first control unit 110. Hence, according to the first optical sensing element 104 without outputting an electrical signal, the first control unit 110 is capable of determining which horizontal position existed with an object due to a travel of the first light beam B1 is interrupted.
Similarly, the second light beam B2 generated by the fifth one of the plurality of second light emitting elements 103 is interrupted by the finger F of the user. Therefore, the interrupted second light beam B2 is unable to be received by the corresponding one of the plurality of second optical sensing elements 105, and the remaining second light beams B2 other than the interrupted second light beam B2 generated by the fifth one of the plurality of second light emitting elements 105 are respectively received by the corresponding one of the plurality of second optical sensing elements 105, and thus only those of the second optical sensing elements 105 receiving the second light beams B2 output the corresponding electrical signals to the second control unit 111. Hence, according to the second optical sensing element 105 without outputting an electrical signal, the second control unit 111 is capable of determining which vertical position existed with the object due to a travel of the second light beam B2 is interrupted. As a result of the principle mentioned above, the first control unit 110 and the second control unit 111 can determine a location of the finger F of the user and output a trigger signal corresponding to the location of the finger F. The operation of the conventional optical touch panel 10 is as disclosed above.
However, the conventional optical touch panel 10 have to dispose with a significant amount of the first light emitting elements 102, the second light emitting elements 103, the first optical sensing elements 104 corresponding to the first light emitting elements 102 and the second optical sensing elements 105 corresponding to the second light emitting elements 103 for sensing the location of the finger F of the user. Hence, the conventional optical touch panel 10 is necessarily requires a higher cost. Similarly, the conventional optical touch device with the conventional optical touch panel has the same disadvantages. Accordingly, it is desired to provide an optical touch panel and an optical touch device capable of being manufactured with lower cost.